Main Page | Modules | Namespace List | Class Hierarchy | Class List | File List | Namespace Members | Class Members | File Members | Related Pages
lens_calibrate/HermiteSpline.h
Go to the documentation of this file.00001 /* HermiteSpline.h 16 Feb 2008 TKS 00002 00003 Hermite Spline Interpolation Routines 00004 lifted & adapted from John Burkardt's collection at 00005 http://people.scs.fsu.edu/~burkardt/cpp_src/spline/spline.html 00006 NOTE FORTRAN style 1-origin array indexing 00007 00008 */ 00009 /* Copyrignt (C) 2008, 2009 Thomas K Sharpless 00010 * tksharpless@gmail.com 00011 * 00012 * This program is free software; you can redistribute it and/or 00013 * modify it under the terms of the GNU General Public 00014 * License as published by the Free Software Foundation; either 00015 * version 2 of the License, or (at your option) any later version. 00016 * 00017 * This software is distributed in the hope that it will be useful, 00018 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00019 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00020 * General Public License for more details. 00021 * 00022 * You should have received a copy of the GNU General Public 00023 * License along with this software; if not, write to the Free Software 00024 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 00025 * 00026 */ 00027 00028 #ifndef _HERMITESPLINE_H 00029 #define _HERMITESPLINE_H 00030 00031 00032 #ifdef __cplusplus 00033 extern "C" { 00034 #endif 00035 00036 /* tabulate coefficients for Hermite spline interpolation of y(t) 00037 tdata[ndata], ydata[ndata] are tabulated y{t} values 00038 ypdata[ndata] are its 1st derivatives at same t's (how you set 00039 these determines the curviness of the spline) 00040 Note t values must be monotonic but intervals can vary 00041 Returns pointer to a new array c[4*ndata] of coefficients 00042 Note c[4*ndata] is to be allocated by caller 00043 */ 00044 double * spline_hermite_set ( double c[], int ndata, double tdata[], double ydata[], double ypdata[] ); 00045 00046 /* compute hermite spline interpolation 00047 tdata[ndata] = tabulated t values; c[4*ndata] = coefficients 00048 tval = interpolation point 00049 sval -> returned interpolated y value 00050 spval -> returned derivative at that point (0: no derivative computed) 00051 returns 0: bad input or 1: sucess 00052 */ 00053 int spline_hermite_val ( int ndata, double tdata[], double c[], 00054 double tval, double * sval, double * spval ); 00055 00056 /* set tangents (1st divided differences) for a tabulated function 00057 whose tabulation interval need not be uniform. 00058 these can serve as the derivatives for setting up a spline. 00059 00060 Input: ndata, tdata[ndata], ydata[ndata] as above. 00061 ypdata[ndata] -- place for the result 00062 00063 returns 0 if tdata[] is not monotonic or ndata < 2 or the 00064 range of t or y is < 1e-11, else 00065 1 if ydata[] is monotonic, else 00066 -1 if ydata[] is not monotonic 00067 00068 If y is monotonic, the tangents are adjusted to ensure that all 00069 interpolated values will be monotonic as well. 00070 00071 */ 00072 int spline_tangents_set( int ndata, double tdata[], double ydata[], double ypdata[] ); 00073 00074 /* Find the interval (if any) in t[n] that contains x 00075 t[] must be monotonic ascending or descending 00076 returns i if x == t[i] 00077 returns index (0:n-2) of the left end of the interval, or 00078 -1 if x is out of range 00079 -2 if t is not monotonic 00080 method: linear interpolation search 00081 */ 00082 int findInterval( int n, double t[], double x ); 00083 00084 00085 #ifdef __cplusplus 00086 } 00087 #endif 00088 00089 #endif //ndef _HERMITESPLINE_H 00090 00091
